OpenRaiser/Intern-Atlas huggingface dataset:
Salience-Affected Neural Networks
Venue: arXiv cs.NE 2010
Year: 2010

We present a simple neural network model which combines a locally-connected feedforward structure, as is traditionally used to model inter-neuron connectivity, with a layer of undifferentiated connections which model the diffuse projections from the human limbic system to the cortex. This new layer makes it possible to model global effects such as salience, at the same time as the local network processes task-specific or local information. This simple combination network displays interactions between salience and regular processing which correspond to known effects in the developing brain, such as enhanced learning as a result of heightened affect. The cortex biases neuronal responses to affect both learning and memory, through the use of diffuse projections from the limbic system to the cortex. Standard ANNs do not model this non-local flow of information represented by the ascending systems, which are a significant feature of the structure of the brain, and although they do allow associational learning with multiple-trial, they simply don't provide the capacity for one-time learning. In this research we model this effect using an artificial neural network (ANN), creating a salience-affected neural network (SANN). We adapt an ANN to embody the capacity to respond to an input salience signal and to produce a reverse salience signal during testing. This research demonstrates that input combinations similar to the inputs in the training data sets will produce similar reverse salience signals during testing. Furthermore, this research has uncovered a novel method for training ANNs with a single training iteration.
Practical Parallel External Memory Algorithms via Simulation of Parallel Algorithms
Venue: arXiv cs.DC 2010
Year: 2010

This thesis introduces PEMS2, an improvement to PEMS (Parallel External Memory System). PEMS executes Bulk-Synchronous Parallel (BSP) algorithms in an External Memory (EM) context, enabling computation with very large data sets which exceed the size of main memory. Many parallel algorithms have been designed and implemented for Bulk-Synchronous Parallel models of computation. Such algorithms generally assume that the entire data set is stored in main memory at once. PEMS overcomes this limitation without requiring any modification to the algorithm by using disk space as memory for additional "virtual processors". Previous work has shown this to be a promising approach which scales well as computational resources (i.e. processors and disks) are added. However, the technique incurs significant overhead when compared with purpose-built EM algorithms. PEMS2 introduces refinements to the simulation process intended to reduce this overhead as well as the amount of disk space required to run the simulation. New functionality is also introduced, including asynchronous I/O and support for multi-core processors. Experimental results show that these changes significantly improve the runtime of the simulation. PEMS2 narrows the performance gap between simulated BSP algorithms and their hand-crafted EM counterparts, providing a practical system for using BSP algorithms with data sets which exceed the size of RAM.
Real Interference Alignment
Venue: arXiv cs.IT 2010
Year: 2010

In this paper, we show that the total Degrees-Of-Freedoms (DOF) of the $K$-user Gaussian Interference Channel (GIC) can be achieved by incorporating a new alignment technique known as \emph{real interference alignment}. This technique compared to its ancestor \emph{vector interference alignment} performs on a single real line and exploits the properties of real numbers to provide optimal signaling. The real interference alignment relies on a new coding scheme in which several data streams having fractional multiplexing gains are sent by transmitters and interfering streams are aligned at receivers. The coding scheme is backed up by a recent result in the field of Diophantine approximation, which states that the convergence part of the Khintchine-Groshev theorem holds for points on non-degenerate manifolds.
Dimensionnement des messages dans un reseau mobile opportuniste
Venue: arXiv cs.NI 2010
Year: 2010

Understanding transport capacity in intermittently connected mobile networks (ICMN) is crucial since different applications have different interactivity and bandwidth requirements. One practical issue is how to transform an application's messages into packets suitable for transport over an ICMN. In this paper, we propose a new Markovian model for random temporal graphs and show, both analytically and by replaying a real life trace obtained in a rollerblading tour, that the size of the messages sent over an ICMN has a decisive impact on their delivery ratio. A given message could therefore be broken down into smaller packets to increase reliability. However, we also show that this gain in reliability only appears under tight constraints on the maximum delay tolerated. Mobile application designers should therefore balance message size against both application requirements and network topology dynamics to improve performance.
Relay Assisted Cooperative OSTBC Communication with SNR Imbalance and Channel Estimation Errors
Venue: arXiv cs.IT 2010
Year: 2010

In this paper, a two-hop relay assisted cooperative Orthogonal Space-Time Block Codes (OSTBC) transmission scheme is considered for the downlink communication of a cellular system, where the base station (BS) and the relay station (RS) cooperate and transmit data to the user equipment (UE) in a distributed fashion. We analyze the impact of the SNR imbalance between the BS-UE and RS-UE links, as well as the imperfect channel estimation at the UE receiver. The performance is analyzed in the presence of Rayleigh flat fading and our results show that the SNR imbalance does not impact the spatial diversity order. On the other hand, channel estimation errors have a larger impact on the system performance. Simulation results are then provided to confirm the analysis.
Interestingness Measure for Mining Spatial Gene Expression Data using Association Rule
Venue: arXiv cs.DB 2010
Year: 2010

The search for interesting association rules is an important topic in knowledge discovery in spatial gene expression databases. The set of admissible rules for the selected support and confidence thresholds can easily be extracted by algorithms based on support and confidence, such as Apriori. However, they may produce a large number of rules, many of them are uninteresting. The challenge in association rule mining (ARM) essentially becomes one of determining which rules are the most interesting. Association rule interestingness measures are used to help select and rank association rule patterns. Besides support and confidence, there are other interestingness measures, which include generality reliability, peculiarity, novelty, surprisingness, utility, and applicability. In this paper, the application of the interesting measures entropy and variance for association pattern discovery from spatial gene expression data has been studied. In this study the fast mining algorithm has been used which produce candidate itemsets and it spends less time for calculating k-supports of the itemsets with the Boolean matrix pruned, and it scans the database only once and needs less memory space. Experimental results show that using entropy as the measure of interest for the spatial gene expression data has more diverse and interesting rules.
Estimation of Defect proneness Using Design complexity Measurements in Object- Oriented Software
Venue: arXiv cs.SE 2010
Year: 2010

Software engineering is continuously facing the challenges of growing complexity of software packages and increased level of data on defects and drawbacks from software production process. This makes a clarion call for inventions and methods which can enable a more reusable, reliable, easily maintainable and high quality software systems with deeper control on software generation process. Quality and productivity are indeed the two most important parameters for controlling any industrial process. Implementation of a successful control system requires some means of measurement. Software metrics play an important role in the management aspects of the software development process such as better planning, assessment of improvements, resource allocation and reduction of unpredictability. The process involving early detection of potential problems, productivity evaluation and evaluating external quality factors such as reusability, maintainability, defect proneness and complexity are of utmost importance. Here we discuss the application of CK metrics and estimation model to predict the external quality parameters for optimizing the design process and production process for desired levels of quality. Estimation of defect-proneness in object-oriented system at design level is developed using a novel methodology where models of relationship between CK metrics and defect-proneness index is achieved. A multifunctional estimation approach captures the correlation between CK metrics and defect proneness level of software modules.
Infocast: A New Paradigm for Collaborative Content Distribution from Roadside Units to Vehicular Networks Using Rateless Codes
Venue: arXiv cs.NI 2010
Year: 2010

In this paper, we address the problem of distributing a large amount of bulk data to a sparse vehicular network from roadside infostations, using efficient vehicle-to-vehicle collaboration. Due to the highly dynamic nature of the underlying vehicular network topology, we depart from architectures requiring centralized coordination, reliable MAC scheduling, or global network state knowledge, and instead adopt a distributed paradigm with simple protocols. In other words, we investigate the problem of reliable dissemination from multiple sources when each node in the network shares a limited amount of its resources for cooperating with others. By using \emph{rateless} coding at the Road Side Unit (RSU) and using vehicles as data carriers, we describe an efficient way to achieve reliable dissemination to all nodes (even disconnected clusters in the network). In the nutshell, we explore vehicles as mobile storage devices. We then develop a method to keep the density of the rateless codes packets as a function of distance from the RSU at the desired level set for the target decoding distance. We investigate various tradeoffs involving buffer size, maximum capacity, and the mobility parameter of the vehicles.
Secure Communication in Stochastic Wireless Networks
Venue: arXiv cs.IT 2010
Year: 2010

Information-theoretic security -- widely accepted as the strictest notion of security -- relies on channel coding techniques that exploit the inherent randomness of the propagation channels to significantly strengthen the security of digital communications systems. Motivated by recent developments in the field, this paper aims at a characterization of the fundamental secrecy limits of wireless networks. Based on a general model in which legitimate nodes and potential eavesdroppers are randomly scattered in space, the intrinsically secure communications graph (iS-graph) is defined from the point of view of information-theoretic security. Conclusive results are provided for the local connectivity of the Poisson iS-graph, in terms of node degrees and isolation probabilities. It is shown how the secure connectivity of the network varies with the wireless propagation effects, the secrecy rate threshold of each link, and the noise powers of legitimate nodes and eavesdroppers. Sectorized transmission and eavesdropper neutralization are explored as viable strategies for improving the secure connectivity. Lastly, the maximum secrecy rate between a node and each of its neighbours is characterized, and the case of colluding eavesdroppers is studied. The results help clarify how the spatial density of eavesdroppers can compromise the intrinsic security of wireless networks.
Multistage Relaying Using Interference Networks
Venue: arXiv cs.IT 2010
Year: 2010

Wireless networks with multiple nodes that relay information from a source to a destination are expected to be deployed in many applications. Therefore, understanding their design and performance under practical constraints is important. In this work, we propose and study three multihopping decode and forward (MDF) protocols for multistage half-duplex relay networks with no direct link between the source and destination nodes. In all three protocols, we assume no cooperation across relay nodes for encoding and decoding. Numerical evaluation in illustrative example networks and comparison with cheap relay cut-set bounds for half-duplex networks show that the proposed MDF protocols approach capacity in some ranges of channel gains. The main idea in the design of the protocols is the use of coding in interference networks that are created in different states or modes of a half-duplex network. Our results suggest that multistage half-duplex relaying with practical constraints on cooperation is comparable to point-to-point links and full-duplex relay networks, if there are multiple non-overlapping paths from source to destination and if suitable coding is employed in interference network states.
Fault Tolerance in Real Time Multiprocessors - Embedded Systems
Venue: arXiv cs.OS 2010
Year: 2010

All real time tasks which are termed as critical tasks by nature have to complete its execution before its deadline, even in presence of faults. The most popularly used real time task assignment algorithms are First Fit (FF), Best Fit (BF), Bin Packing (BP).The common task scheduling algorithms are Rate Monotonic (RM), Earliest Deadline First (EDF) etc.All the current approaches deal with either fault tolerance or criticality in real time. In this paper we have proposed an integrated approach with a new algorithm, called SASA (Sorting And Sequential Assignment) which maps the real time task assignment with task schedule and fault tolerance
Gradient Based Seeded Region Grow method for CT Angiographic Image Segmentation
Venue: arXiv cs.CV 2010
Year: 2010

Segmentation of medical images using seeded region growing technique is increasingly becoming a popular method because of its ability to involve high-level knowledge of anatomical structures in seed selection process. Region based segmentation of medical images are widely used in varied clinical applications like visualization, bone detection, tumor detection and unsupervised image retrieval in clinical databases. As medical images are mostly fuzzy in nature, segmenting regions based intensity is the most challenging task. In this paper, we discuss about popular seeded region grow methodology used for segmenting anatomical structures in CT Angiography images. We have proposed a gradient based homogeneity criteria to control the region grow process while segmenting CTA images.
Fault Tolerant Real Time Systems
Venue: arXiv cs.PF 2010
Year: 2010

Real time systems are systems in which there is a commitment for timely response by the computer to external stimuli. Real time applications have to function correctly even in presence of faults. Fault tolerance can be achieved by either hardware or software or time redundancy. Safety-critical applications have strict time and cost constraints, which means that not only faults have to be tolerated but also the constraints should be satisfied. Deadline scheduling means that the taskwith the earliest required response time is processed. The most common scheduling algorithms are :Rate Monotonic(RM) and Earliest deadline first(EDF).This paper deals with the interaction between the fault tolerant strategy and the EDF real time scheduling strategy.
A Study of VLSI Technology, Wafers and Impact on Nanotechnology
Venue: arXiv cs.OH 2010
Year: 2010

This paper presents a detailed study of the present VLSI technological aspects, importance and their replacement or combination with the Nanotechnology in the VLSI world of silicon semiconductors. Here authors bring out the nanotechnology in Silicon world which invariably means shrinking geometry of CMOS devices to nano scale. This also refers to a new world of nanotechnology where chemists are working in manufacturing of carbon nanotubes , nano devices of varius materials of nano dimensions without even knowing how this could change the whole world of Si and CMOS technology and the world we live in.
Cooperative Proxy Servers Architecture for VoD to Achieve High QoS with Reduced Transmission Time and Cost
Venue: arXiv cs.MM 2010
Year: 2010

- The aim of this paper is to propose a novel Voice On Demand (VoD) architecture and implementation of an efficient load sharing algorithm to achieve Quality of Service (QoS). This scheme reduces the transmission cost from the Centralized Multimedia Sever (CMS) to Proxy Servers (PS) by sharing the videos among the proxy servers of the Local Proxy Servers Group [LPSG] and among the neighboring LPSGs, which are interconnected in a ring fashion. This results in very low request rejection ratio, reduction in transmission time and cost, reduction of load on the CMS and high QoS for the users. Simulation results indicate acceptable initial startup latency, reduced transmission cost and time, load sharing among the proxy servers, among the LPSGs and between the CMS and the PS.
An Architectural Approach for Decoding and Distributing Functions in FPUs in a Functional Processor System
Venue: arXiv cs.AR 2010
Year: 2010

The main goal of this research is to develop the concepts of a revolutionary processor system called Functional Processor System. The fairly novel work carried out in this proposal concentrates on decoding of function pipelines and distributing it in FPUs as a part of scheduling approach. As the functional programs are super-level programs that entails requirements only at functional level, decoding of functions and distribution of functions in the heterogeneous functional processor units are a challenge. We explored the possibilities of segregation of the functions from the application program and distributing the functions on the relevant FPUs by using address mapping techniques. Here we pursue the perception of feeding the functions into the processor farm rather than the processor fetching the instructions or functions and executing it. This work is carried out at theoretical levels and it requires a long way to go in the realization of this work in hardware perhaps with a large industrial team with a pragmatic time frame.
Comparison of Genetic Algorithm and Simulated Annealing Technique for Optimal Path Selection In Network Routing
Venue: arXiv cs.NE 2010
Year: 2010

This paper addresses the path selection problem from a known sender to the receiver. The proposed work shows path selection using genetic algorithm(GA)and simulated annealing (SA) approaches. In genetic algorithm approach, the multi point crossover and mutation helps in determining the optimal path and also alternate path if required. The input to both the algorithms is a learnt module which is a part of the cognitive router that takes care of four QoS parameters.The aim of the approach is to maximize the bandwidth along the forward channels and minimize the route length. The population size is considered as the N nodes participating in the network scenario, which will be limited to a known size of topology. The simulated results show that, by using genetic algorithm approach, the probability of shortest path convergence is higher as the number of iteration goes up whereas in simulated annealing the number of iterations had no influence to attain better results as it acts on random principle of selection.
Tatouage Robuste Et Aveugle Dans Le Domaine Des Valeurs Singulieres
Venue: arXiv cs.CR 2010
Year: 2010

Digital watermarking consists on inserting a mark into an image to protect it against copies. The heaviness of the extraction procedure with the old methods urged us to look for a new algorithm in the singular values domain which would be blind : it does not require the original image to extract the mark. We propose a new robust method which consists on inserting the bits of the mark into the singular values matrix. Contrary to most of the watermarking algorithms, it is blind and the results show that our method is robust against the JPEG compression, the reduction of colors (GIF) and the histogram spreading. So, we were able to obtain PSNR = 49,63 dB.
A Multi-Stage CUDA Kernel for Floyd-Warshall
Venue: arXiv cs.DC 2010
Year: 2010

We present a new implementation of the Floyd-Warshall All-Pairs Shortest Paths algorithm on CUDA. Our algorithm runs approximately 5 times faster than the previously best reported algorithm. In order to achieve this speedup, we applied a new technique to reduce usage of on-chip shared memory and allow the CUDA scheduler to more effectively hide instruction latency.
A Simple Message-Passing Algorithm for Compressed Sensing
Venue: arXiv cs.IT 2010
Year: 2010

We consider the recovery of a nonnegative vector x from measurements y = Ax, where A is an m-by-n matrix whos entries are in {0, 1}. We establish that when A corresponds to the adjacency matrix of a bipartite graph with sufficient expansion, a simple message-passing algorithm produces an estimate \hat{x} of x satisfying ||x-\hat{x}||_1 \leq O(n/k) ||x-x(k)||_1, where x(k) is the best k-sparse approximation of x. The algorithm performs O(n (log(n/k))^2 log(k)) computation in total, and the number of measurements required is m = O(k log(n/k)). In the special case when x is k-sparse, the algorithm recovers x exactly in time O(n log(n/k) log(k)). Ultimately, this work is a further step in the direction of more formally developing the broader role of message-passing algorithms in solving compressed sensing problems.
A Decidable Class of Nested Iterated Schemata (extended version)
Venue: arXiv cs.LO 2010
Year: 2010

Many problems can be specified by patterns of propositional formulae depending on a parameter, e.g. the specification of a circuit usually depends on the number of bits of its input. We define a logic whose formulae, called "iterated schemata", allow to express such patterns. Schemata extend propositional logic with indexed propositions, e.g. P_i, P_i+1, P_1, and with generalized connectives, e.g. /ı=1..n or i=1..n (called "iterations") where n is an (unbound) integer variable called a "parameter". The expressive power of iterated schemata is strictly greater than propositional logic: it is even out of the scope of first-order logic. We define a proof procedure, called DPLL*, that can prove that a schema is satisfiable for at least one value of its parameter, in the spirit of the DPLL procedure. However the converse problem, i.e. proving that a schema is unsatisfiable for every value of the parameter, is undecidable so DPLL* does not terminate in general. Still, we prove that it terminates for schemata of a syntactic subclass called "regularly nested". This is the first non trivial class for which DPLL* is proved to terminate. Furthermore the class of regularly nested schemata is the first decidable class to allow nesting of iterations, i.e. to allow schemata of the form /ı=1..n (/\j=1..n ...).
"Compressed" Compressed Sensing
Venue: arXiv cs.IT 2010
Year: 2010

The field of compressed sensing has shown that a sparse but otherwise arbitrary vector can be recovered exactly from a small number of randomly constructed linear projections (or samples). The question addressed in this paper is whether an even smaller number of samples is sufficient when there exists prior knowledge about the distribution of the unknown vector, or when only partial recovery is needed. An information-theoretic lower bound with connections to free probability theory and an upper bound corresponding to a computationally simple thresholding estimator are derived. It is shown that in certain cases (e.g. discrete valued vectors or large distortions) the number of samples can be decreased. Interestingly though, it is also shown that in many cases no reduction is possible.